Add a file observer to monitor if there is a crash

chrome/android/java/src/org/chromium/chrome/browser/crash/MinidumpDirectoryObserver.java

Index: chrome/android/java/src/org/chromium/chrome/browser/crash/MinidumpDirectoryObserver.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/crash/MinidumpDirectoryObserver.java b/chrome/android/java/src/org/chromium/chrome/browser/crash/MinidumpDirectoryObserver.java
new file mode 100644
index 0000000000000000000000000000000000000000..6464083b107b78a37e63dc029c2fb1258ddc8bc1
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/crash/MinidumpDirectoryObserver.java
@@ -0,0 +1,58 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.crash;
+
+import android.content.Context;
+import android.content.Intent;
+import android.os.Build;
+import android.os.FileObserver;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.Log;
+import org.chromium.base.PathUtils;
+import org.chromium.base.metrics.RecordUserAction;
+
+import java.io.File;
+
+/**
+ * The FileObserver to monitor the minidump directory.
+ */
+public class MinidumpDirectoryObserver extends FileObserver {
+
+    private static final String TAG = "MinidumpDirObserver";
+    private static Context sContext = ApplicationStatus.getApplicationContext();
+
+    public static final String MINIDUMP_EXPERIMENT_NAME = "AddMinidumpDirObserver";
+
+    public MinidumpDirectoryObserver() {
+        // The file observer detects MOVED_TO for child processes.
+        super(new File(PathUtils.getCacheDirectory(sContext),
+                CrashFileManager.CRASH_DUMP_DIR).toString(), FileObserver.MOVED_TO);
+    }
+
+    /**
+     *  When a minidump is detected, upload it to Google crash server
+     */
+    @Override
+    public void onEvent(int event, String path) {
+        // This is executed on a thread dedicated to FileObserver.
+        if (CrashFileManager.isMinidumpMIMEFirstTry(path)) {
+            try {
+                Intent intent = MinidumpUploadService.createFindAndUploadLastCrashIntent(sContext);
+                sContext.startService(intent);
+                Log.i(TAG, "Detects a new minidump %s send intent to MinidumpUploadService", path);
+                RecordUserAction.record("MobileBreakpadUploadAttempt");
+            } catch (SecurityException e) {
+                // For KitKat and below, there was a framework bug which cause us to not be able to
+                // find our own crash uploading service. Ignore a SecurityException here on older
+                // OS versions since the crash will eventually get uploaded on next start.
+                // crbug/542533
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+                    throw e;
+                }
+            }
+        }
+    }
+}